When a person's heart does not function normally due to, for example, a genetic or acquired condition, various treatments may be prescribed to correct or compensate for the condition. For example, pharmaceutical therapy may be prescribed for a patient or a pacemaker or similar device may be implanted in the patient to improve the function of the patient's heart.
In conjunction with such therapy it may be desirable to detect conditions in or apply therapy to one or more chambers of the heart. For example, an implanted device may sense electrical activity in a chamber and, based on the sensed conditions, apply an electrical stimulus to a chamber. Similarly, an implanted device may measure cardiac pressure in a given chamber in an attempt to determine how the heart is functioning. Then, based on the pressure reading, the patient's therapy may be modified to compensate for any undesirable conditions. For example, if cardiac pressure is measured over time, the operation of an implanted cardiac device such as a cardioverter defibrillator may be adjusted, as necessary, according to conditions diagnosed as a result of the pressure measurements.
Traditionally, access to one or more chambers of the heart has been gained via the venous system. That is, a cardiac lead is inserted into a vein and then routed through the venous system to a chamber on the right side of the heart.
In some cases, however, it is desirable to sense conditions or provide treatment to a chamber on the left side of the heart. For example, left atrial pressure has been identified as a potential indicator for left ventricular failure. Access to the left side of the heart may be obtained from the right side of the heart by routing a lead through a septal wall that separates a right chamber from a left chamber. Accordingly, there is a need for an effective mechanism that provides access to the left side of the heart via a transseptal technique.